1. Field of the Invention
The present invention relates to a process of identifying an ovulation phase within the menstrual cycle of a woman, and more particularly to a process of measuring several times in direct succession a direct current potential between two spaced apart portions of the body of the woman and evaluating the measurements to identify the ovulation phase.
2. Description of the Prior Art
Medical experiments wherein direct current potentials between two spaced apart portions of the human body were measured, date back more than 30 years from the present.
Early medical researchers have proven conclusively that direct current potential or voltage differences of approximately 1-100 milivolts magnitude may exist between different portions of the human body. Efforts were made in the prior art to find a correlation between variations and time dependent fluctuations of these voltage differences and changes in the physiological state of human beings.
The different nature of experiments measuring skin resistance as in the use of polygraph type devices, and measuring potential differences between different points of the human body was recognized early in the prior art.
An article authored by H. S. Burr et al titled "Bio-Electric Correlates of Human Ovulation" appeared in the Yale Journal of Biology and Medicine Vol. 10 pages 155-160 (1937). This article described an experiment wherein the potential or voltage difference between the symphysis pubis and the vagina of a healthy adult woman was monitored for 4 days preceding ovulation. The experiment showed that prior to ovulation the potential of the vagina has shifted from a negative to a positive value. The authors suggested that a technique of monitoring the above described potential difference makes a determination of the time of ovulation possible.
In an article authored by Louis Langman et al titled "A Technique to Aid in the Detection of Malignancy of the Female Genital Tract", American Journal of Obstetrics and Gynecology, St. Louis, Volume 57, pages 274-281, 1949, the authors described experiments aimed at determining or predicting malignancy in the female genital tract. Potential or voltage differences between the cervix and the ventral abdominal wall were measured. The authors found, among other things, that in healthy patients a negative potential of the genital tract could be correlated with ovulation.
U.S. Pat. No. 3,920,003 describes an apparatus for detecting small electrical potential differences between the vagina and another location of the body. One of the asserted uses of the apparatus is the detection of ovulation. The patent disclosure states that the potential of the vagina is negative with respect to other parts of the body, but this potential may fall to zero or reverse in sign when ovulation occurs. The patent suggests the monitoring of the potentials between the vagina and other points of the body for the purpose of detection of ovulation.
U.S. Pat. No. 3,924,609 describes an apparatus and a method for detecting the phase of ovulation in a mammalian female, including the human female. The method employs a voltmeter whose electrodes are brought into contact with fingers of each hand of the woman. This disclosure teaches that prior to ovulation the measured potential from a negative value normally rises towards and even above zero, and reaches a peak at the time of ovulation. A potential-versus-time graph as depicted in this prior art patent is substantially reproduced in the present application as FIG. 3 for the sake of graphically showing the state of the prior art.
In attempting to measure potential differences of 1-100 milivolt magnitude between various points of the human body, great care must be taken. A voltage meter having a very high impedance and of at least 10 megaohms which draws practically no current, must be utilized. Furthermore contaminating contact potentials which may arise on contact of an electrode with the skin must be avoided or compensated for. The prior art has generally recognized this. The above cited article in the Yale Journal of Biology and Medicine describes the use of silver--silver chloride electrodes as skin contacts. More specifically, silver electrodes which were coated with silver chloride were brought into contact with the human skin through the intermediacy of a saline solution bridge.
An electrical circuit which is suitable for measuring low voltages associated with the human body is described e.g. in U.S. Pat. Nos. 3,924,609 and 3,920,003. Recent advances in microprocessor or "chip" technology as well as advances in the flat panel information display technology have made possible corresponding advances in volt meter design technology.
Although, as it was described above, the prior art suggested various methods for the detection of the ovulation phase of the human menstrual cycle, the prior art methods have not gained widespread acceptance. The reliability of the prior methods has not been adequately proven. Furthermore, the inconvenience associated with some of the prior art methods, such as insertion of an electrode into the vagina, has understandably discouraged the widespread use of these methods. Many healthy women merely seek an aid in family planning through the accurate detection of their ovulation cycle and are reluctant to use inconvenient methods. Accordingly, there is room in the art for the improved ovulation detection method of the present invention.